An optical disc has received attention as a memory medium that becomes a core in the recent rapid development of multimedia. The optical disc is loaded into an optical disc drive to perform reading/writing of data from/to the optical disc by means of an optical pickup head.
In order to improve the reliability of optical discs, it is necessary to store and reproduce high-quality signals to and from the optical discs. If there is a tilt angle of a recording surface of the optical disc with respect to an optical axis of a lens of the optical pickup head, then an aberration occurs in a light spot converged on the optical disc. As such, it becomes difficult to record and reproduce high-quality signals on the optical disc. Therefore, in order to record and/or reproduce high-quality signals to and/or from the optical disc, it is necessary to detect the aforementioned tilt angle accurately and to then correct this tilt angle.
As shown in FIG. 4, a conventional optical pickup head 100 includes a lens 90, a lens holder 80, several metal wires 70, a bracket 60, and a base 50. The lens 90 is held by the lens holder 80, and the lens holder 80, in turn, is suspended by the metal wires 70. The metal wires 70 are fixed in the bracket 60 extending upward from the base 50. A pair of magnets 81 is respectively secured to two lateral sides of a bottom of the lens holder 80. Opposite to the corresponding magnet 81, a yoke 51 with a coil 53 wound thereon extends upwardly from the base 50. Two ends of the coil 53 are connected to a power supply (not shown). A magnetic field may thereby be induced when a current is supplied to the coil 53. When the optical pickup head 100 is reading or recording an optical disc (not shown), a detector (not shown) detects a tilt angle between the optical disc and an optical axis of the lens 90, and a controller (not shown) controls a magnitude and direction of a current outputted by the power supply based on the detected tilt angle. As the output voltage of the power supply varies, the induced magnetic field of the coil 53 varies accordingly. An attraction interaction or a repulsion interaction between the magnet 81 and the coil 53 results in a position change of the lens holder 80, so that a tilt adjustment is achieved.
The optical pickup head 100 adopts an electromagnetic tilt adjusting device. Besides the tilt adjusting device, most optical pickup heads also have a focus adjusting device and a track adjusting device. The focus adjusting device and the track adjusting device are usually electromagnetic adjusting devices. If the optical pickup 100 has another electromagnetic adjusting device besides the electromagnetic tilt adjusting device, a magnetic interference may arise between such electromagnetic devices.
Therefore, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.